CN113342053A - Aircraft airspeed calibration method - Google Patents

Aircraft airspeed calibration method Download PDF

Info

Publication number
CN113342053A
CN113342053A CN202110721942.9A CN202110721942A CN113342053A CN 113342053 A CN113342053 A CN 113342053A CN 202110721942 A CN202110721942 A CN 202110721942A CN 113342053 A CN113342053 A CN 113342053A
Authority
CN
China
Prior art keywords
airspeed
course
angle
route
waypoint
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202110721942.9A
Other languages
Chinese (zh)
Inventor
赵艳平
肖良华
陈瑶
陈蕊
徐良
夏斌
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Chengdu Aircraft Industrial Group Co Ltd
Original Assignee
Chengdu Aircraft Industrial Group Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Chengdu Aircraft Industrial Group Co Ltd filed Critical Chengdu Aircraft Industrial Group Co Ltd
Priority to CN202110721942.9A priority Critical patent/CN113342053A/en
Publication of CN113342053A publication Critical patent/CN113342053A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D1/00—Control of position, course or altitude of land, water, air, or space vehicles, e.g. automatic pilot
    • G05D1/10—Simultaneous control of position or course in three dimensions
    • G05D1/101—Simultaneous control of position or course in three dimensions specially adapted for aircraft

Abstract

The invention discloses a method for calibrating the airspeed of an airplane, which relates to the technical field of airspeed detection of airplanes and comprises the following steps: the method comprises the following steps: drawing a forward course from waypoint a to waypoint b, and drawing a return course from waypoint b to waypoint a; step two: determining the airspeed of the departure route as Va1The airspeed of the return route is Va2And the airspeed is ensured to be unchanged; step three: obtaining the included angle theta between the airspeed and the ground speed in the course of departure1Angle theta between airspeed and ground speed in return route2(ii) a Step four: determining the magnitude V of the airspeeda(ii) a Step five: will find VaV actually measured by airspeed sensora1、Va2The invention has the advantages of simplicity, convenience, rapidness, accuracy, strong generalization and the like, can calibrate the airspeed sensor by only acquiring few flight parameters, and has strong maneuverability.

Description

Aircraft airspeed calibration method
Technical Field
The invention relates to the technical field of aircraft airspeed detection, in particular to an aircraft airspeed calibration method.
Background
The airspeed is a measure of the magnitude of aerodynamic force applied to the aircraft, is a pneumatic parameter that the aircraft must acquire, and can be generally obtained by measuring total pressure and static pressure through an airspeed sensor. The airspeed sensor is generally installed at the aircraft nose position, and the flow that its perception is disturbed greatly by the aircraft nose, and the measurement result has certain error, uses often to calibrate through standard airspeed tube. The standard airspeed tube calibration method needs to be supported by a large number of test flights, and the cost is high; on the other hand, the standard airspeed head still has errors caused by machine head disturbance, and the errors cannot be completely eliminated fundamentally.
According to flight dynamics, the track speed of the mass center of the airplane when the airplane flies in the air
Figure BDA0003136794020000011
(i.e. ground speed, abbreviated as ground speed), flying speed
Figure BDA0003136794020000012
(airspeed, referred to herein as airspeed) and wind speed
Figure BDA0003136794020000013
The relationship among the three is shown as the formula:
Figure BDA0003136794020000014
in the formula, ground speed
Figure BDA0003136794020000015
The method is a known quantity, can be obtained by a sensor such as a GPS and the like, and has high precision. Because the round trip time is short, the wind speed and the direction can be considered to be kept unchanged, and therefore, the high-precision airspeed value can be obtained theoretically by using the formula.
At present, when the reciprocating constant-speed flat flight is applied to calibrating airspeed in engineering practice, the airspeed and the wind speed are always considered to be coincident, namely the vector included angle between the airspeed and the wind speed is 0 degree or 180 degrees, and the airplane is in a downwind or upwind state, so that the vacuum speed can be solved by using a simple scalar sum calculation method. In fact, in order to meet the conditions, the air route of the airplane must be adjusted, so that the airspeed and the wind speed direction are coincident, and the difficulty and the complexity of test flight planning are increased; or the flight path is not adjusted, the flight hourly space velocity and the wind speed direction of the airplane are not coincident, but the directions of the flight hourly space velocity and the wind speed are considered to be coincident during calibration calculation, so that an error is caused, and under most flight conditions, the wind speed and the airspeed direction are not coincident, namely, the airplane is in crosswind. Therefore, it is necessary to provide a method for calibrating the airspeed of an aircraft, which can solve the airspeed with high accuracy without paying attention to whether the wind speed and the airspeed direction coincide, so as to calibrate the airspeed sensor.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a method for calibrating the airspeed of an airplane, so that the vacuum speed can be solved with high precision without paying attention to whether the wind speed and the airspeed direction coincide, and the effect of calibrating the airspeed sensor is achieved.
In order to solve the technical problems, the invention adopts the following technical scheme:
a method of aircraft airspeed calibration, comprising the steps of:
the method comprises the following steps: drawing a forward course from waypoint a to waypoint b, and drawing a return course from waypoint b to waypoint a;
step two: determining the airspeed of the departure route as Va1The airspeed of the return route is Va2And the airspeed is guaranteed to be constant, i.e.
Figure BDA0003136794020000021
Step three: obtaining the included angle theta between the airspeed and the ground speed in the course of departure1Angle theta between airspeed and ground speed in return route2；
Step four: determining the magnitude V of the airspeeda：
According to the formula
Figure BDA0003136794020000022
Comprises the following steps:
Figure BDA0003136794020000023
the wind speed can be eliminated by differentiating the two equations in the formula (1), and the following results are obtained:
Figure BDA0003136794020000024
squaring both sides of the equation of equation (2) yields:
Figure BDA0003136794020000031
in the formula (I), the compound is shown in the specification,
Figure BDA0003136794020000032
is the ground speed of the outbound route,
Figure BDA0003136794020000033
the ground speed of the return route;
step five: v obtained by equation (3)aV actually measured by airspeed sensora1、Va2For comparison, the difference is determined:
ΔV1＝Va-Va1，ΔV2＝Va-Va2 (4)
Δ V in formula (4)1And Δ V2Namely the airspeed correction value, and calibrating the airspeed sensor according to the airspeed correction value.
Preferably, in step one, the distance between waypoint a and waypoint b is less than or equal to 10 km.
Preferably, in step two, the airspeed V of the outbound routea1And airspeed V of the return routea2All are obtained by airspeed sensors.
Preferably, in step three, θ1、θ2The yaw angle, the course angle and the sideslip angle can be obtained, and the relation is as follows:
θ1＝ψ1+ψa1+β1，θ2＝ψ2+ψa2+β2 (5)
in the formula, #1Yaw angle, psi, for course goinga1Is the heading angle, beta, of the course of the departure1For sideslip angle, psi, of course of departure2Yaw angle, psi, for the return coursea2Is the course angle, beta, of the return course2Is the sideslip angle of the return route.
Preferably, the yaw angle is obtained by a gyroscope, the heading angle is determined by the planned route, and the sideslip angle is obtained by a sideslip angle sensor.
Preferably, in step four, the ground speed of the departure route
Figure BDA0003136794020000034
And ground speed of the return route
Figure BDA0003136794020000035
All acquired by a GPS sensor.
Preferably, in step four, θ is when the airspeed direction coincides with or is close to coinciding with the ground speed direction, i.e. the airspeed direction also coincides with or is close to coinciding with the wind speed direction1+θ2Very small, cos (θ)1+θ2) 1, then equation (3) reduces to:
Figure BDA0003136794020000041
the invention has the beneficial effects that:
1. by the method, the vacuum speed can be solved by only designing the flight path of the plane without paying attention to whether the wind speed and the airspeed direction are coincident or not when the plane is planned for test flight, so that the difficulty and the complexity of the planning for test flight are reduced; in addition, the method does not introduce new errors, and improves the precision of airspeed calibration compared with the existing airspeed calibration method; the design method has the characteristics of simplicity, convenience, rapidness, accuracy, strong universality and the like, can calibrate the airspeed only by acquiring few flight parameters, and has strong maneuverability.
2. When the airspeed is calibrated, the airspeed can be accurately calculated by the formula (3), wherein
Figure BDA0003136794020000042
And
Figure BDA0003136794020000043
all are directly acquired by the GPS sensor, so that only theta needs to be calculated1、θ2I.e., and theta1、θ2Can be obtained from a yaw angle, a course angle and a sideslip angle, wherein the yaw angle can be directly obtained by a gyroscope, the course angle is determined by a planning course, the sideslip angle is obtained by a sideslip angle sensor, and V is obtainedaThen, the airspeed correction value delta V in the formula (4) is finally obtained1And Δ V2And the airspeed sensor can be calibrated according to the airspeed correction value, so that the difficulty and complexity of test flight planning are reduced, and the airspeed calibration precision is improved.
Drawings
In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.
Fig. 1 is a schematic view of the present invention for a round-trip constant speed flat flight.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
The parameter factors involved in the invention are as follows:
Figure BDA0003136794020000051
examples
As shown in fig. 1, the present embodiment provides a method for calibrating an airspeed of an aircraft, including the following steps:
the method comprises the following steps: drawing a forward course from waypoint a to waypoint b, and drawing a return course from waypoint b to waypoint a; this process is called one-trip constant-speed level flight;
step two: determining the airspeed of the departure route as Va1The airspeed of the return route is Va2And the airspeed is guaranteed to be constant, i.e.
Figure BDA0003136794020000052
When the airplane flies horizontally at a constant speed back and forth, the ground speed is ensured to be coincident with the flight path by the airplane;
step three: obtaining the included angle theta between the airspeed and the ground speed in the course of departure1Angle theta between airspeed and ground speed in return route2；
Step four: determining the magnitude V of the airspeeda：
Because the round-trip time is short, the wind speed can be considered to be kept unchanged in both magnitude and direction, namely the wind speeds are all
Figure BDA0003136794020000061
Then according to the formula
Figure BDA0003136794020000062
Comprises the following steps:
Figure BDA0003136794020000063
the wind speed can be eliminated by differentiating the two equations in the formula (1), and the following results are obtained:
Figure BDA0003136794020000064
squaring both sides of the equation of equation (2) yields:
Figure BDA0003136794020000065
in the formula (I), the compound is shown in the specification,
Figure BDA0003136794020000066
is the ground speed of the outbound route,
Figure BDA0003136794020000067
the ground speed of the return route;
according to the formula (3), the airspeed V can be obtained by performing one-time reciprocating constant-speed flat flightaThe direction of airspeed may be from1、θ2Represents;
step five: v obtained by equation (3)aV actually measured by airspeed sensora1、Va2For comparison, the difference is determined:
ΔV1＝Va-Va1，ΔV2＝Va-Va2 (4)
Δ V in formula (4)1And Δ V2Namely the airspeed correction value, and calibrating the airspeed sensor according to the airspeed correction value.
By the method, the vacuum speed can be solved only by designing the flight path of the plane without paying attention to whether the wind speed and the airspeed direction are coincident or not when the plane is planned for test flight, so that the difficulty and complexity of the planning for test flight are reduced; in addition, new errors are not introduced in the method, and compared with the existing airspeed calibration method, the method improves the accuracy of airspeed calibration; the design method has the characteristics of simplicity, convenience, rapidness, accuracy, strong universality and the like, can calibrate the airspeed only by acquiring few flight parameters, and has strong maneuverability.
Specifically, in the first step, the distance between the waypoint a and the waypoint b is less than or equal to 10km, the test flight distance is reasonably controlled, the difficulty is reduced, and the calibration precision is improved.
Specifically, in the second step, the airspeed V of the outbound routea1And airspeed V of the return routea2All obtained from airspeed sensors, i.e. Va1And Va2Is a known value.
Specifically, in the third step, θ1、θ2The yaw angle, the course angle and the sideslip angle can be obtained, and the relation is as follows:
θ1＝ψ1+ψa1+β1，θ2＝ψ2+ψa2+β2 (5)
in the formula, #1Yaw angle, psi, for course goinga1Is the heading angle, beta, of the course of the departure1For sideslip angle, psi, of course of departure2Yaw angle, psi, for the return coursea2Is the course angle, beta, of the return course2Is the sideslip angle of the return route.
It should be noted that the definitions of the yaw angle, the heading angle, and the sideslip angle are explicitly described in the flight dynamics of the aircraft, and are not described herein again, where for the sideslip angle, generally, a laterally-oriented statically-stable aircraft usually flies without sideslip in the air, and thus the sideslip angle does not need to be obtained.
Specifically, the yaw angle is obtained by a gyroscope, the course angle is determined by a planned route, the sideslip angle is obtained by a sideslip angle sensor, the obtaining mode is simple and efficient, and the precision can be guaranteed.
In particular, in said fourth step, the ground speed of the departure route
Figure BDA0003136794020000072
And ground speed of the return route
Figure BDA0003136794020000073
All acquire by GPS sensor, the acquisition mode is simple high-efficient.
Specifically, in the fourth step, θ is calculated when the airspeed direction coincides with or is close to coinciding with the ground speed direction, that is, the airspeed direction also coincides with or is close to coinciding with the wind speed direction1+θ2Very small, cos (θ)1+θ2) 1, then equation (3) reduces to:
Figure BDA0003136794020000071
here, formula (6) is a specific example of formula (3).
According to the invention, when the formula (3) is applied, the vacuum speed can be solved without paying attention to whether the wind speed and the airspeed direction coincide, as the ground speed and the yaw angle of the airplane can be directly obtained by the GPS sensor and the gyroscope respectively, and the course angle is determined by the planned route, the precision is high, the airspeed precision obtained by the formula (3) is higher, and the calibration of the airspeed sensor of the airplane can be realized by taking the airspeed precision as the basis.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.

Claims (7)

1. A method of aircraft airspeed calibration, comprising the steps of:
the method comprises the following steps: drawing a forward course from waypoint a to waypoint b, and drawing a return course from waypoint b to waypoint a;
step two: determining the airspeed of the departure route as Va1The airspeed of the return route is Va2And the airspeed is guaranteed to be constant, i.e.
Figure FDA0003136794010000011
Step three: obtaining the included angle theta between the airspeed and the ground speed in the course of departure1Angle theta between airspeed and ground speed in return route2；
Step four: determining the magnitude V of the airspeeda：
According to the formula
Figure FDA0003136794010000012
Comprises the following steps:
Figure FDA0003136794010000013
the wind speed can be eliminated by differentiating the two equations in the formula (1), and the following results are obtained:
Figure FDA0003136794010000014
squaring both sides of the equation of equation (2) yields:
Figure FDA0003136794010000015
Figure FDA0003136794010000016
Figure FDA0003136794010000017
in the formula (I), the compound is shown in the specification,
Figure FDA0003136794010000018
is the ground speed of the outbound route,
Figure FDA0003136794010000019
the ground speed of the return route;
step five: v obtained by equation (3)aV actually measured by airspeed sensora1、Va2For comparison, the difference is determined:
ΔV1＝Va-Va1，ΔV2＝Va-Va2 (4)
Δ V in formula (4)1And Δ V2Namely the airspeed correction value, and calibrating the airspeed sensor according to the airspeed correction value.
2. The method of claim 1, wherein in step one, the distance between waypoint a and waypoint b is less than or equal to 10 km.
3. A method of aircraft airspeed calibration as claimed in claim 1, wherein in step two, the airspeed V of the outbound routea1And airspeed V of the return routea2All are obtained by airspeed sensors.
4. A method of aircraft airspeed calibration according to claim 1, wherein in step three, θ1、θ2The yaw angle, the course angle and the sideslip angle can be obtained, and the relation is as follows:
θ1＝ψ1+ψa1+β1，θ2＝ψ2+ψa2+β2 (5)
in the formula, #1Yaw angle, psi, for course goinga1Is the heading angle, beta, of the course of the departure1For sideslip angle, psi, of course of departure2To return toYaw angle, psi, of coursea2Is the course angle, beta, of the return course2Is the sideslip angle of the return route.
5. The method of claim 4, wherein the yaw angle is obtained from a gyroscope, the heading angle is determined from a planned route, and the sideslip angle is obtained from a sideslip angle sensor.
6. An aircraft airspeed calibration method as claimed in claim 1, wherein in step four, the ground speed of the outbound route
Figure FDA0003136794010000021
And ground speed of the return route
Figure FDA0003136794010000022
All acquired by a GPS sensor.
7. An aircraft airspeed calibration method according to claim 1, wherein in step four, θ is determined when the airspeed direction coincides with or is close to coinciding with the ground speed direction, i.e., the airspeed direction also coincides with or is close to coinciding with the wind speed direction1+θ2Very small, cos (θ)1+θ2) 1, then equation (3) reduces to:
Figure FDA0003136794010000023
CN202110721942.9A 2021-06-28 2021-06-28 Aircraft airspeed calibration method Pending CN113342053A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110721942.9A CN113342053A (en) 2021-06-28 2021-06-28 Aircraft airspeed calibration method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110721942.9A CN113342053A (en) 2021-06-28 2021-06-28 Aircraft airspeed calibration method

Publications (1)

Publication Number Publication Date
CN113342053A true CN113342053A (en) 2021-09-03

Family

ID=77479227

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110721942.9A Pending CN113342053A (en) 2021-06-28 2021-06-28 Aircraft airspeed calibration method

Country Status (1)

Country Link
CN (1) CN113342053A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113533784A (en) * 2021-09-07 2021-10-22 成都飞机工业（集团）有限责任公司 GPS (global positioning system) round-trip non-constant-speed flat flight airspeed calibration method
CN115856359A (en) * 2023-02-15 2023-03-28 成都凯天电子股份有限公司 Online correction method for airspeed of helicopter

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108152529A (en) * 2017-11-02 2018-06-12 成都飞机工业（集团）有限责任公司 A kind of method based on flight parameter calculation of wind speed and wind direction

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108152529A (en) * 2017-11-02 2018-06-12 成都飞机工业（集团）有限责任公司 A kind of method based on flight parameter calculation of wind speed and wind direction

Non-Patent Citations (7)

* Cited by examiner, † Cited by third party
Title
AM CHO，等: ""Air data system calibration using GPS velocity information"", 《2012 12TH INTERNATIONAL CONFERENCE ON CONTROL, AUTOMATION AND SYSTEMS》 *
ANDREW J. KNOEDLER，等: ""Investigation Of Global Positioning System Use For Air Data System Calibration"", 《PROCEEDINGS OF POSITION, LOCATION AND NAVIGATION SYMPOSIUM》 *
刘华勇，等: ""空速的GPS试飞校准方法"", 《航空学报》 *
宋攀，等: ""基于GPS的运输类飞机全空速范围校准方法研究"", 《科技创新与应用》 *
尹文强，等: ""基于飞行试验的无人机空速系统误差修正研究"", 《飞机设计》 *
杨欢: ""GPS法空速校准试飞数据处理与分析"", 《2017年（第三届）中国航空科学技术大会论文》 *
郗超，等: ""基于GPS的侧风影响下的空速校准方法研究"", 《航空科学技术》 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113533784A (en) * 2021-09-07 2021-10-22 成都飞机工业（集团）有限责任公司 GPS (global positioning system) round-trip non-constant-speed flat flight airspeed calibration method
CN113533784B (en) * 2021-09-07 2022-01-25 成都飞机工业（集团）有限责任公司 GPS (global positioning system) round-trip non-constant-speed flat flight airspeed calibration method
CN115856359A (en) * 2023-02-15 2023-03-28 成都凯天电子股份有限公司 Online correction method for airspeed of helicopter

Similar Documents

Publication Publication Date Title
US8718971B2 (en) System for determining the airspeed of an aircraft
EP2434296B1 (en) Airspeed sensing system for an aircraft
EP1256812B1 (en) Sideslip correction for a multi-function three probe air data system
CN113342053A (en) Aircraft airspeed calibration method
US20060178790A1 (en) High-altitude capable wide velocity range flight velocity vector measurement probe and measurement system
JP2007263962A (en) Fan atmospheric air data system with duct
US10352813B2 (en) Calibration of aircraft instruments using a laser sensor
EP3581942B1 (en) Dual channel air data system with inertially compensated backup channel
CN110346605B (en) Method and system for aircraft airspeed calibration based on static pressure error correction
CN111221347B (en) Acceleration compensation method and system in attitude estimation of vertical take-off and landing fixed wing unmanned aerial vehicle
US20210132103A1 (en) Method and apparatus for estimating an airspeed of a rotorcraft by analyzing its rotor
CN109725649A (en) One kind determining high algorithm based on barometer/IMU/GPS Multi-sensor Fusion rotor wing unmanned aerial vehicle
CN111625021A (en) Unmanned aerial vehicle power line patrol distance measurement system and method based on electromagnetic field
CN103424125A (en) Method for measuring reference installation error of optical axis of unmanned aerial vehicle
Jost et al. Flush air data system-an advanced air data system for the aerospace industry
CN114778887A (en) Unmanned aerial vehicle wind measurement method and device based on improved triangular vector model
CN113484542B (en) Single-point rapid calibration method for three-dimensional velocimeter
CN113525711B (en) Method for identifying aerodynamic focus of aircraft through flight test
Jain et al. Calibration and accuracy determination of airdata system for a modern fighter aircraft
Cho et al. Air data system calibration using GPS velocity information
CN114877881A (en) Fusion method and fusion system for course angle measurement data of unmanned aerial vehicle
Colgren et al. Flight Test validation of sideslip estimation using inertial accelerations
Krylov et al. System of air signals of aircraft with stationary non-protrusive flow receiver
Jain et al. Extended Kalman filter based Air Data System (ADS) table update for fighter aircraft
Saraf et al. Calibration and accuracy determination of airdata system for a modern fighter

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication

Application publication date: 20210903

RJ01 Rejection of invention patent application after publication